 |
FEEDBACK (Tue 26 Dec 06 @ 01:28:01) |
 |
FEEDBACK
--------------------------------------------------------------------------------
Communications / Electroacoustics
Any process in which the output depends functionally on itself (i.e. on the input). Feedback may be positive or negative; positive when the SIGNAL feedback is in PHASE with the input signal, and negative when it is in phase opposition (i.e. out of phase) with the input. Positive feedback is normally undesirable for AMPLIFIERs, for while the GAIN is increased, it is usually at the expense of stability and FIDELITY. Negative feedback, while cancelling part of the input, improves FREQUENCY RESPONSE, lowers DISTORTION and NOISE.
Feedback also refers to a process of behaviour modification in which information received about the behaviour and its effect influences future behaviour. This concept plays an important role in the field of cybernetics, and has influenced the design of servomechanisms, theories of learning, and work in artificial intelligence and computing science, among others.
In a similar sense, feedback can describe the process by which an individual receives acoustic information about the environment, information which is used for orientation with respect to it. Lack of acoustic feedback (in the sense of reflected sound) as experienced in an ANECHOIC CHAMBER may explain reactions of fear and disorientation that are reported. |
